As a collision avoidance support apparatus, the following apparatus disclosed in Japanese patent document 1 is known, for example, which determines a selling regarding whether or not to provide a warning according to the distance to a nearby vehicle that is traveling in the adjacent lane.
Japanese patent document 1: JP 3,872,033
However, when a warning was provided by the above collision avoidance support apparatus, the driver of the vehicle can understand that lane-changing is not possible right now, but cannot have a clue of how to change lanes safely. That is, the driver has to determine by him/herself how to change lanes safely in traffic. In otherwords, the driver's load for changing lanes after the warning is, not reduced by the above-described collision avoidance support apparatus.